N-substituted fatty acid amide lubricants

ABSTRACT

THIS INVENTION RELATES TO N-ACYLMORPHOLINES AND NMONO AND N,N-DISUBSTITUTED FATTY ACID AMIDES AND TO SIMILAR DERIVATIVES OF EPITHIOAMIDES WHICH ARE USEFUL AS BASE AND EXTREME PRESSURE LUBRICANTS AND ADDITIVES.

United States Patent Otfice 3,809,706 Patented May 7, 1974 3,809,706N-SUBSTITUTED FATTY ACID AMIDE LUBRICANTS Frank C. Magne, Robert R. Mod,and Gene Sumrell, New Orleans, La., and Winfred E. Parker, Philadelphia,Pa., assignors to the United States of America as represented by theSecretary of Agriculture No Drawing. Original application Aug. 31, 1971,Ser. No. 176,734, now Patent No. 3,746,644. Divided and this applicationApr. 6, 1973, Ser. No. 348,802

Int. Cl. C071? 9/02, 9/10 U.S. Cl. 260-403 1 Claim ABSTRACT OF THEDISCLOSURE This invention relates to N-acylmorpholines and N- mono andN,N-disubstituted fatty acid amides and to similar derivatives ofepithioamides which are useful as base and extreme pressure lubricantsand additives.

This is a division of application Ser. No. 176,734 filed Aug. 31, 1971,now Pat. No. 3,746,644.

A non-exclusive, irrevocable, royalty-free license in the inventionherein described, throughout the world for all purposes of the UnitedStates Government, with the power to grant sublicenses for suchpurposes, is hereby granted to the Government of the United States ofAmerica.

This invention relates to certain compounds which are N-fatty acylderivatives of primary and secondary amine and N-substituted acylderivatives of primary and secondary amines which have exhibited utilityas base lubricants, extreme pressure lubricants or lube additives. Moreparticularly, this invention relates to N- and N,N-disubstituted longchain aliphatic amides the acyl component of which is a normal,branched, or substituted alkenoic or alkanoic acyl 'group containingfrom 16 to 22 carbon atoms the amide nitrogen of which may be derivedfrom an alkyl amine, dialkyl amine, alkylalkoxyalkylamine,dialkoxyalkylamine or nitrogen heteroalicyclic. Typical amines arebutylamines, dibutylamines, N-methyl-alkoxyethyl amine, di-ethoxyethylamine, and morpholine. The acyl substituent referred to may be divalentsulfur or pentavalent phosphorus. I

We have discovered that many of the simple N-alkyl and N,N-dialkyl orN-alkyl-N-alkoxyalkyl amides of the C to C alkeneoic or alkanoic fattyacids are good base lubricants. We have further discovered that theintroduction of divalent sulfur into the fatty acid moiety impartsexcellent extreme pressure lubricant characteristics to such compounds.In particular we have found the epithio group to be most eifective. Wehave also observed that the introduction of both hydroxy and alkylphosphato groupings alpha to each other also imparts extreme pressurelubricant characteristics to the compound.

In addition it was noted that the above hydroxyphosphato compound andits mercapto analog N-[9(10)- mercapto-(9)IO-dibutylphosphato]stearamidewere efiective antiwear compounds and additives.

Inclued among the specific compounds operable as base lubricants areN-methyl-N-butyloleamide, -N-ethoxyethoxyethoxy propyloleamide,N-ethoxyethoxy propyloleamide, N-methoxyisopropyloleamide,N-rnethoxyethyloleamide. Compounds showing particular promise as extremepressure lubricants. or additives are N,N-dibutyl- 9,10-epithiostearamide, N,N-dibutyl-9, 10-12, 13-diepithiostearamide, 9,10-epithiostearoy1 morpholine, N-

ethoxyethoxyethoxypropyl-9, IO-epithiostearamide, n- 9, 10-12,13-diepithiostearoylmorpholine and N-[9(10)- hydroxy-9 10)-dibutylphosphato] stearamide.

Compounds showing particular promise as antiwear additives areN,N-dibutyl-[9( l0)-hydroxy-(9) IO-dibutylphosphato]stearamide andN,N-[9(l0)mercapt0-(9) 10- dibutylphosphatostearoyl]morpholine.

Example 1 N-methyl-N-butyloleamide.-- grams (0.33 mole) of oleoylchloride was added dropwise and with stirring to a mixture of 29 grams(0.33 mole) of N-methyl-N- butylamine and 27 grams (0.33 mole) ofpyridine. Stirring was continued until the heat of reaction subsided.The solid pyridine hydrochloride was filtered otf and the filtrate waswashed successively with aqueous HCl and water until acid free. It wasdried stripped, percolated through an activated alumina column, and theproduct removed from the percolate by stripping ofi the solvent.Analysis of the product (percent): C, 78.87 (theory 78.63); H, 13.02(theory 12.82); N, 3.96 (theory 3.99).

Example 2 N,N-dibutyloleamide.-'Ihis material was prepared by theprocedure of Example 1 from 100 grams (0.33 mole) of oleoyl chloride42.5 grams (0.33 mole) of di-n-butylamine and 27 grams (0.33 mole)pyridine. Analysis of the product (percent): C, 78.94 (theory 79.25); H,13.16 (theory 13.06); N, 3.44 (theory 3.56) confirm the preparation.

Example 3 Ethoxyethoxyethoxy propyloleamide.--This material was preparedby the procedure of Example 1 from 100 grams (0.33 mole) of oleoylchloride, 73.0 grams (0.33 mole) ethoxyethoxyethoxy-propylamine and 27.0grams (0.33 mole) pyridine. Analysis (percent): C, 71.84 (theory 72.04);H, 11.80 (theory 11.80); and N, 2.96 (theory 2.90) confirm thepreparation.

Example 4 Ethoxyethoxypropyloleamide.This material was prepared by theprocedure of Example 1 from 100 grams (0.33 mole) of oleoyl chloride,58.3 grams (0.33 mole) ethoxyethoxypropylamine and 27.0 grams (0.33mole) of pyridine. Analysis (percent): C, 71.45 (theory 73.80); H, 11.87(theory 12.07); and N, 2.92 (theory 3.18) confirm the preparation.

Example 5 Methoxyisopropyloleamide-This material was prepared by theprocedure of Example 1 from 100 grams (0.33 mole) of oleoyl chloride,29.3 grams (0.33 mole) methoxyisopropylamine and 27.0 grams (0.33 mole)pyridine. Analysis (percent): C, 73.15 (theory 74.99); H, 12.01 (theory11.93); and N, 3.67 (theory 3.97) confirm the preparation.

Example 6 Methoxyethyloleamide.--This material was prepared by theprocedure of Example 1 from 100 grams (0.33 mole) of oleoyl chloride,24.4 grams (0.33 mole) of methoxyethylamine and 27.0 grams (0.33 mole)pyridine. Analysis (percent): C, 73.08 (theory 74.55); H, 11.98 (theory11.83); and N, 3.31 (theory 4.14) confirm the preparation.

Example 7 Oleoylmorpholine.-This material was prepared by the procedureof Example 1 from 100 grams (0.33 mole) of oleoyl chloride, 28.7 grams(0.33 mole) of morpholine and 27.0 grams (0.33 mole) of pyridine.

3 Example 8 N,N-dibutyloleamider-This product was'p'r'epared fol lowingthe exact procedure of Example 2 except for the substitution of oleoylchloride by linoleoyl chloride.

Example 9 N,N-dibutyl-9,10-epithiostearamide.-l20 grams (0.30 mole) ofN,N-dibutyloleamide was epoxidized by the addition with stirring of 62.0grams (0.36 mole) of metachloroperbenzoic acid in 630 ml. of chloroform.Reaction was continued for 1 hour beyond final addition and the excessperacid destroyed by a small amount of a 10% solution of Na SO Themetachlorobenzoic acid was removed by a NaHCO Wash, followed by waterwashing. The CHCl solution was then dried with anhydrous Na SO and theCHCl stripped off to recover the product N,Ndibutyl-9,10-epoxystearamide, oxirane content 3.45% (theory 3.91%). 100grams (0.24 mole) of this product was added to a well stirred slurry of55.7 g. (0.73 mole) of thiourea and 89.5 g. (0.73 mole) of benzoic acidin acetone. Stirring was continued for 3 hours beyond the terminaladdition whereupon the benzoic acid was washed out with 38.8 g. (0.36mole) of Na CO and the organic product extracted with hexane. The

organic phase extract was dried and stripped to recover the productN,N-dibutyl-9,10-epithiostearamide containing 6.41% sulfur (theory 6.67%

Example 10 N (9,10 epithiostearoyl)morpholine.--This product wasprepared by the exact procedure described in Example 9 except for thesubstitution of oleoylmorpholine for the N,N-dibutyloleamide of Example9. Analysis of product showed (percent): C, 71.22 (theory 69.34); H,11.22 (theory 1077); N, 3.66 (theory 3.68); S, 3.44 (theory 7.80).

Example 11 N,N dibutyl-9,10,12,13 diepithiostearamide.-'Ihis product wasprepared following the procedure described in Example 9 except for thereplacement of the N,N dibutyl oleamide of Example 9 byN,N-dibutyllinoleamide, and a doubling of the molar ratios of allreagents. The product analyzed as follows (percent): C, 69.64 (theory68.57); H, 10.93 (theory 10.76); N, 3.10 (theory 3.07); S, 11.7 (theory14.06).

Example 12 N-ethoxyethoxyethoxypropyl-9,l0-epithiostearamide.- To 166 g.of N-ethoxyethoxyethoxypropyl oleamide, Example 3, was added dropwiseand with stirring 73.8 g of m-chloroperbenzoic acid in 800 ml. of CHClThe spent m-chloroperbenzoic acid was removed with 10% aqueous NaHCO andthe epoxide recovered by drying and stripping off the CHCl 171 g. ofthis epoxide was added dropwise to a slurry of 56 g. thiourea in 1000ml. of acetone and the concurrent addition of 43.4 g. of glacial aceticacid and the reaction mixture stirred for 3 hours. The glacial aceticacid was neutralized with Na CO and the episulfide,N-ethoxyethoxyethoxypropyl- 9,10-epithiostearamide, extracted withSkellysolve B and washed, dried, and stripped. Its elemental analysiswas (percent): C, 67.1 (66.52); H, 11.42 (10.88); N, 2.67 (2.87); S,2.29 (6.57).

Example 13 N ethoxyethoxyethoxypropyl 9(10)mercaptostearamide.--173 g.of N-ethoxyethoxyethoxypropyloleamide in CCL; was treated in the coldwith a CCL, solution con- 5 4 extracted with hexane; washed, dried, andstripped. Elermental..analysis-aoftthe productwas (percent): C, 66.3

(66.5); H, 11.1 (10.9); N, 2.7 (2.9); S, 4.4 (6.8).

Example 14 N,N dibutyl g 9( 10) [dibutylphosphono] stearamide.- g. ofN,N-dibutyloleamide, Example 2, 148 g. of dibutyl vphosphite, and 1.29of benzoyl peroxide catalyst were heated at C. for 3 /2 hours.Additional units of 1.29'g. of benzoyl peroxide was added after thefirst and second hours of reaction time. The excess dibutylphosphite'wasthen removed by distillation at reduced pressure, 0.45 mm.Hg. The stillpot contents showed strong adsorption bonds at 8, 9.3, and9.7 microns characteristics of the phosphonate group. The elementalanalysis was (percent): C, obs. 71.46 (69.50); H, obs. 12.42 (11.92); N,obs. 2.20 (2.38); P, obs. 4.24 (5.28) respectively.

Example 15 N-9,10-12,13-diepithiostearoylmorpholine-This prodnot wasprepared by the same procedure described in Example 9 except'for thesubstitution of linoleoyl morpholine for the N,N-dibutyloleamide ofExample 8 and the doubling of molar proportions of the m-chloroperbenzoic acid in the epoxidation step and the thiourea and benzoicacidin the epithioation step. The elemental analysis was (percent): C,obs. 68.89 (63.92); H, obs. 10.26 (9.44.); N, obs. 3.29 (3.38); S, obs.4.00 (15.49) respectively.

Example 16 N,N-dibutyl- [9 l0) -hydroxy- (9 10-dibutylphosphato]stearamide.44.7 g. of dibutylhydrogen phosphate was added to 182.2 g. ofN,N-dibutyl-9,10-epoxystearamide at 90-95 C. with stirring. Reactionconditions were con-. tinued for 3 /2 hours after termination of theaddition. The reaction product was dissolved in commercial hexane andtheunreacted dibutyl hydrogen hosphate neutralized and washed out withportions of aqueous 10% NaI-IC-O' followed by several water washes.Acidulation of th hexane phase with diluted HCl followed by severalwater washes, drying and stripping, yielded the product. Elementalanalysis was (percent): C, obs. 66.56 (65.91); H, obs. 11.04 (11.30); N,obs. 2.90 (2.26); P, obs. 3.04 (4.20). I Example 17 N [9(10)mercapto(9)1O-dibutyIphosphatostearoyl] morpholine.--l2 g. of dibutylhydrogenphosphate was added dropwise with stirring to 51.0 g. of(9,10-epithiostea'royDmOrphoIine, the preparation of Example 10, at85590 C. and the heating and stirring continued for 3 hours beyond theterminal addition. The reaction product was dissolved in commercialhexane and any excess or unreacted" was neutralized and washed out withaqueous 10% NaHCO .'The 'hexane extract was washed several times withwater dried and stripped. The elemental analysis of the product was(percent): C, obs. 66.74 (69.36); H, obs. 10.69 (11.05); N, obs. 2.89(3.32); S, obs. 3.27 (2.17); P,- obs. 1.68 (2.10) respectively.

Example 18 The compounds prepared in accordance to the procedures givenin Examples 1 through 7 were evaluated as base lubricants 'in' the ShellFour-Ball Wear tests following amodified procedure of ASTM D2266-67. Theresulting scar diameter on the balls after running at 600 r.p. m. for 1hour at C. and 50 kg. load were compared with the scars obtained usingcommercial lubricants such as Aeroshell Mil-L-708 (di-Z-ethylhexylsebacate and additive), Gulfpride, single G, MS, multiviscosity, and 100sec. parafiin oil. The results of these tests are reported in Table I.

TABLE I.--ANTIWEAR LUBRICANT PROPERTIES OF FATTY ACID AMIDES Avg. wearscar, mm.

With- With out addiaddi- Compound tive tive Additive 1.-...N,N-bis(2-ethoxyethyl) 0. 597 0. 735 N,N-di-butyl-9,

oleamide. lo'epithiostearamide.

2..--. N,N-dl-n-butyl-9,10-epi- 0.842 None.

thiostearamlde.

3.-... Oleoy nnorpholine 0.623 0.658 Do.

N,N-dlimethyloleamide. 0. 797 0. 987 Do. ,N-c i-n-propyloleamide. 0. 9080. 885 Do. 6- N,N-diexylolea1n1de-..-. 0. 893 0. 898 Do.,N-dibutylerucamrde... 0.758 0. 798 Do. 8.---- N,N-di-n-buty1 amide of0. 798 0. 958 Do.

sel. hydrogenated cottonseed fatty acids.

9. N,N-bis(2-methoxyethyl) D0.

olearm'de.

10. N,Ndihutyloleamide N-oleoyl-i-propylpiperidine.

. Morpholide of sel. hydrogenated cottonseed fatty acids.

13. N-rnethyl-N-butyloleamlde- 14. N 'ethoxyethoxyethoxypropyloleamide.

15- N-ethoxyethoxypropyleamide.

16. N-methoxyisopropyloleamide.

17- N-methoxyethyloleamlde. 0. 420

18. 102 sec paraflin oil 0. 902 N-rnethoxyethyloleamide.

19...- D.O. 0.906 Do.

20- N,N-dibutyl-9(10)-carbo- 0 610 butoxyoctadeeanamide.

21.-.- 102 sec paratfin oil 0.818 N,N-d1butyl-9(10)-carbobutoxyoctadeeenamide.

22.-.. D.0.S 0.945 Do.

23- N -[9(10)mercapto-(9)10- 0. 615

dibutylphosphatostearoyl] morpholine.

24. 102 see paraflin oil 0. 552 N-[9(10)mercapto- (9)10-dibuty1-phosphatestearoy11morpholine.

25.-.. D.O.S 0.535 Do.

26- N,N-dibutyl-[9(10) -hy- 0. 498

droxy-(9)10 1ibutylphosphato]stearamide.

27. 102 sec paratfin oil 0. 498 N,N-dibutyl-[9 ()-hydroxy-(9)10-dibuty1- phosphate] stearamlde.

28...- D.O.S D0.

phosphono1steeramlde.

30- N-ethoxyethoxyethoxy- 31.N-ethoxyethoxyethoxypropyl-9(10)mercaptostearamide.

32. N-(9,10-12 13-diepithlostearoyl morpholine.

33- Bis(2-ethylhexyl)sebacate.

34- 100 sec paratfin oil Aeroshell (Mil-7808) 0 36..-- Gulipride, SingleG, MS,

multiviscosity.

37- 100 sec paraffin oil 0. 813 N,N-dlbutyl-9,10-12,13-diepithiostearamide.

38. Bis(2-ethylhexyl)sebacate 0.836 Do.

39- 100 see paraflin oil 0. 723 N-9,10-ep1th10- stearoyl morpholine.

40.... Bls(2-ethylhexyl)sebacate 0.915 Do.

41. 100 sec paraffin oil 0. 917 N,N-dibutyl9,

10-dich1orostearamlde.

42- Bis(2-ethylhexyl)sebacate 0. 848 Do.

It can be seen from the data presented that the N- alkoxyalkyl andN,N-di(alkoxyalkyUoleamides, without the assistance of additives,exhibited wear characteristics (i.e., low scar diameters) comparable tothe commercial controls Aeroshell and Gulfpride, which do containadditives to improve performance.N,N-dibutyl-[9(10)-hydroxy-(9)IO-dibutylphosphato]stearamide andN-[9(10) mercapto-(9)1O dibutylpho sphatostearoyl]morpholine 6. not onlyexhibit low wear characteristics in themselves but also impart asadditives such characteristics to paraffin oil and DOS base lubricants.

Example 19 TABLE IL-EXTREME PRESSURE TESTS (ASTM D2596-67T) Weld pointNo addi- With Compound tive 5% #2 1 N,N-bls(2-ethoxyethyl)oleamlde 120170 2- N,N-di-n-butyl-Q,m-epithiostearamide 3- Oleoylmorpholine. 4N,N-dimethyloleamide 5 N,N-di-n-propylol'eamide 6.N,N-di-n-hexyloleamide 7 N,N-di-n-butylerucamide 8. N,N-di-n-butyl amide0t hydrogenated cottonseed fatty acids. 9N,N-bis(2-methoxyethyl)oleamide 10 N-methy1-N-butyl,o1eamide 11N,N-dibuty1-9,10-epithiostearamide 12-N,N-dibutyl-9,10-12,13-diepithiostearamlde...- 13N-ethoxyethoxyethoxypropyloleamide 14 N-ethoxyethoxypropyloleamide. 15N-methoryisopropyloleamide 16. N-methoxyethyloleamide 17.N-QJU-epithiostearoylmorpho 18. B1s(2-ethylhexyl)sebacate 19- 100 secparaflin oil. 20 SAE commercial hypoid flui TABLE III Evaluation ofN,N-dibutyl9,10-12,13-d.ieplthiostearamlde as an additive and as a baseoil in extreme pressure tests. (ASTM D2596-67T) Wear Per cent Load,scar, Base oil additive kg. mm.

sec paraflin oil 5 140 1. 90 Do 5 200 2. 35 5 220 2. 75 5 240 4 Weld 5 151 5 180 1. 59 5 1 190 2. 47 5 200 I Weld 10 240 2. 88 10 260 3. 55 10270 Weld N,N-dibuty1-9,10-12,13-d1epithiostearamide None 120 1. 38 Do.-.None 160 1. 61 Do--. None 200 1. 89 Do. None 280 2. 13 Do.-. None 320 2.47 Do- None 360 2. 70 Do--- None 400 2. 88 Do None 440 7 Weld Extremepressure tests on N-ethoxyethyoxyethoxypropyl-9,10-epithiostearemide(PC-O-No. 7682) Applied Avg. load, scar, Base oil Additive kg. mm.

None 120 1.05 None 160 v 1. 75 None 240 2.35 None 300 2. 19 None 3402.55 None 360 2. 62 None 380 Weld 7682 (5%) 120 2.28 (5%) 2. 46 7682(5%) Weld 682 (5%) 120 2.23 7682 (5%) 140 2.44 (5 150 Weld See footnotesat end of table.

TABLE IIIContinued TABLE lll continrued Extreme pressure tests onN-[9(10)-mercapto-9(10)-dibutylphosphato igfg 22i stearoyflmorpholiue(PC-O-No. 7687) I Base 011 Additive kg. mm. None 120 608 None 160 1. 45Extreme pressure tests on N-ethoxyethoxyethox ropyl-9(l0)-mercapto- None200 1. stearamide (P C-O-No. 768 None 240 1. None 280 3. 36

None 200 1. 54

None 300 2. 26 Extreme pressure tests on N,N-dibutyl-9(l0)-carbobutoxyoetadecan None 400 2. 25 amide (PC-O-No. 7688) None 450 2.15 None 500 I 2. 15 None 1. 92 None 2. 18 120 1. 97 None 2. 45 140 2. 35None Weld 150 2. 54 160 Weld 1 Incipient seizure. 120 1 68 1 Teststopped because of extreme decomposition. Did not weld. 140 8 Teststopped because of extreme decomposition and noxious fumes. 160 5g 15Did not weld. 72 4 5 seconds. m 6 4 seconds.

a 0 10 seconds.

1 46 seconds.

Extreme pressure tests on N-(9,10-12,l3-diepithiostearoyDmorpholine I(PC-O-No. 7684) N 200 2 21 20 TABLE IV v N83: 2 0 2: 33 Evaluation ofN-9,1(}epithiostearoyl morpholine as an additive and as 9.

N 340 2 43' base oil in extreme pressure tests (ASTM D 2596'67T) N 2. 75N832 2, 90 Percent Load, Wear N 500 2 2' 9g Base oil additive kg. scar,mm.

7684 (5%) i 100 2. 23 I 25 100 see. parafiin oil 5 120 2.00 7684 (5%)120 2.61 D0 5 140 2. 80 7684 (5%) 2. 74 5 160 3. 25 7684 (5%) Weld 5 180l Weld 7 50 e 5 160 94 7684 (57) 140 2. 53 5 180 00 3 59;? 160 77 5 200Weld 5 170 C1 e None 120 0. .70 None 200 2. 13 Extreme pressure tests onN,N-dibutyl- (l0)-(dibutylphospnouo N n 240 2. 43 stearamide (PC-O-No.7685) None 300 68 None 380 a Weld 76 85 None 120 3. 05 7685 140 50 1 10seconds. I 5 seconds. 3 50 seconds.

7685 None Weld Extreme pressure tests on N,N-dibutyl-[9(10)-hydroxy-9(llD-dibutyl- 40 We claimh h t t 'd PC-O-N .7686 p 1. Thecompound N,N-d1butyl-9(10)-[d1butylph0s 5 83: gig I 2%; phono]stearamideuseful as a lubricant base. 1 3 2 2'?) f 31 d 0119 None 360 Weld 45 Re fe 100 s par fl 1332 (3%) 2 3.33 3 189 2 s??? STA'ZES r 0 ,6 8 1 Kni-gtet a 260-403 38: .1323? Ei; hi3 215 3,211,766 10/1965 Magne et a1.260403 no.5 7686 (5%) 120 L95 3,538,123 11/1970 Mod et a1. 260-403 D.O.S7686 5% 140 2.86 50 D.O.S- 7686 0 ELBERT L. ROBERTS, Primary ExaminerD.0.S rose (5% Weld

